Sighting device



J. B. HENDERS'QN Sept. 8, 1925.

SIGHTINGA DEVICE Filed Juiy' 26, 1919 4 Sheets-Shea?I l m ZZ, r/zeys Sept. s, 1925.

. y 1,553,077 J, B. HENDERSON SIGHTING DEVICE Filed'July 26. 1919 4 Sheets-Sheet 2` l/V VEN TO R dm ewkldg um SIGHTING DEVICE Filed July 2 6, 1.919

4 Sheets-Sheet 3 l/vVa/v TUR 4 Sheets-Sheet 4 J. B. HENDERSON SIGHTING DEVICE Filed July 2e, 191s l Sept. 8, 1925-.

/V VENTOR I Patented -Sept. 8., 1925.

f UNITED STATES PATENT .ol-F. lcl-a.

JAMES BLacxLocx HENDERSON, or LEE, ENGLAND.

SIGHTING DEVICE.

Application led July 26, 1919. Serial N'o. 313,542.

(emma man m rnovxsxons or rxr. ser or lanen a, 1921, 41 surft., ma.)

Tofall whomv it may concern.'

,Be it'known that I, JAMES BLAc'xLooK -I-IENDER'soN, a subject ofthe Kin of Great Britain, residing at 2, Cambri ge Road, Lee, in the county of Kent, England, have invented certain new and useful further Improvements in Sighting Devices (for which I have filed an application in England #16,669 on November th, 1915), of which, the following is a Specification.

The object of my invention isto improve sighting devices such as gun-sights, bombdroppers, range-Linders, position-finders, artificial horizons or in general any optical sighting device for use on board ship or on an air-ship or aeroplane or on any other moving platform, by eliminating the elects of the angular motion vof the ship, 4aerotion the external object sighte plane or platform, so vthat the image of the target or other object viewed through the telescope, may be stationary in the4 focal plane of the telescope irres ective of this angular motion. `In'the fol owin descri will e called the target and l.the moving platform will be called the shi The present invention relates to (1) improvements in the telescope itself whereby the optical deinitioniis improved and remains equally good throughoutv the roll of the ship so long as the image of the target is visible in the telescope, (2) im rovements by meansA of which .the image o .the target is visible throughout` a greater angle of roll,

(3) improved means for compensating for the effects of straying of the gyroscope or inertia bar on thev image of the target in the telescope, (4) improvements in the methodof compensating for the effects of straying of the gyroscope on the time of firing the-guns in automatic director orrgun sights, (5) improved means for altering the range of the guns in automatic director or I gun sight-s2 (6) improvements in periscopic Sights, perlscopes or dial sights whereby the image of the targetl remains Stationary on the cross wires irrespective of the rolling rof the ship. y

Fig. 1 is a central' elevation through one form of sight constructed in accordance with my invention.

`Fi0n 2, is a section of Fig. 1 approximate y upon the line 2.-2.

lFig 3, is an end view vof Fig. 1 with part lof thecasing removed to more clearly show the optical parts.

cal arrangement which is s ecially -suitable for use with periscopic sig ts.

The main frame of the telescope consists of a disc 1, carrying a circular tubular projection 2 which serves as the case of the telescope and also as the support of the instrument because this tubev screws on to the bracket 3 which is mounted on the sight pedestal. The telescope consists of the ob- ]ective. 4 and the eyepiece 4 Fig. 3) carried by the ring 5 which fits on the outside of the tube 2 vbut is capable of being turned relatively to this tube, oval slots being cut in the tube to pass the telescope beam. The prisms 6 and ofthe telescope are rigidly attached to the prism plate 8 which is pivoted on the frame l on the ball bearing). Compound with the prism plate but on the opposite side of the disc 1, is the cylinder 10. The prism plate and cylinder are stabilized by a gyroscope in its casing 11 (Fig. 1) which fits into a ring 11a supported on a horizontal trunnion axis .12 on the gimbal ring 13 so that the gyro rotor axis is approximately vertical.k The gimbal ring is supported at one end by the trunnion lil which slides into the prism plate axiallyy and at the other end by'a trunnion 15 which slides axially in a bearing 16, supported from the disc 1 by the U bracket 1T. The gyro 11 and its supporting ring 11, have small gravitational stability on the trunnions 12 due to the weight 3 1 and the trunnion axis 12 is below the level of the trunnion axis 14-15 so as to give increased -stability about the latter axis.

The prism plate 8 has an angular adjustment relatively to the trunnion 14 of the Fig.i3, is a plan of the telescope portion I gimbal ring. This mav be brought about in several dilferent ways but in Fig. 1 it is brought about by a roller 1S carried by a short pillar 19 attached to the gimbal ring 13. vThis roller engages in a helical slot in the cylinder 10 so that when the gimbal ring is slid bodily in the direction of the axis ot the trunnions lll- 15, the prism plate turns about the axis of these trunnions. This translation ot' the gimbal ring as a whole is brought about b-y the screw 20 which rocks the lever 2l about its fulcrum on pillar 22 and moves the upper end of the lever to the right or left according as the screw 2O is screwed in or out. The upper end of the lever 21 bears against a ball centre attached to the gimbal ring, concentric with the trunnion 14, and the similar lever 23 presses against a similar ball centre concentric with the trunnion 15. The spring 25 acting through the lever 23 and its fulcruni on the pillar 24 serves to keep the gimbal ring always Apressed against the lever 21 and the lever 21 pressed against the screw 20.

VThe gyro 11 can be caused to process about the trunnion axis 12 by means ot the handle 27 which lits on the end ot' the trunnion 15, outside the cover,v 26. It can 'also be caused to preccss about the trunnion axis 14-1 5, by means of one or other ofthe two levers 28 which can be turned by the earn 29 and the handle 30 (Fig. 2) projecting through-the cover 26. Each level' 28 is .titted with a T head as shown in Fig. 2 and when the T head touches the weight 31a atl tached to the gyro case 11 the gyro processes round the trunnions 14-15, and carries the prism plate 8 with it. This precession is only used as a very rough adjustment, the screw 20 providing the fine adjustment. The gyro rotor axis is kept approximately perpendicular to the gimbal v'ring' 13 by means y of the handle 27 the relative position of the gyro case and gimbal ring being indicated by the pointers and scales 31 (Fig. 1) which are visible through theV windows 32 in the outer cover 26.

The electricl current may be led in to the gyrol by flexible insulated connections at each trunnion or by insulated spring plug connections incorporated in the trunnions, but which since they form no part of this invention are not shown in the drawing.

The switch controlling the tiring circuit of a gun consists of a switch plate 33 which is pivotally mounted on a cylindrical sleeve 34 on the disc 1 concentric with tllewlisr. A small angular motion of the switch plate 33 round the disc centre can be brought about by means of the pin 35 which projects through a 4slot in the disc. The switch plate carries the levers 36 and 37 which are pivotally mounted on their respective tulcra 3.8

and 39 and are interconnected by the link 40, so that a small angular motion -of lever 36 produces a larger angular motion of lever 37. The angular motion of the lever 36 is produced by the trigger 41 which is carried by the trigger plate 10 engaging with one or other o the two small pins 42--43 on the lever 36; a small angular motion of the lever is thus produced'at'ter the manner of an escapement. The lever 37 carries, insulated on its end, the fork 44 which supports a small metal cross 45 on pivots 46 and the cross carries two small rollers 47 and 48 attached to a common spindle passing through the cross. The roller 48 is slightly smaller in diameter than 47 because of its smaller' distance from the lt'ulcrum 39. These rollers roll over the surface of the two semi-circular metal segments 49 and 5U which are insulated from each other and also from the switch plate 33 by whirh they are carried. The line of insulation between the two segments is seen; in Fig. 2 to be inclined to the lever 37 in its central position so that during the motion ot' this lever the roller 47 is for a short time touching the plate 4t) whilethe roller 4S is touching the plate 50. 'lhe spindle of the two rollers then serves as the electrical connection between the two plates and closes the firing circuit either directly or through a relay.

The motionot' the switch plate about the sleeve 34 serves to bring the closing of the firing circuit into phase with the passage of the target across the cross wires of the oridnary layers telescope in director control.

When the sight is mounted directly on a gun I may apply a tangent screw adjustment to this motion of the switch plateand graduate the tangent screw in ranges It the telescope be kept on the target after setting the range Aand if the un be slowly elevated it will fire when 1t reaches the proper elevation for the particular range oi the target.

The optical advantages of the above arrangement of telescope over those described in my revious British Patents Nos. 3683` and 697 of 1915 are (l) the objective and eyepiece are normally on the same level and 'the parallax error due to any angular motion of the disc 1 round the trunnion 14 is less than it would be if the objective and eyepiece were not normally on the same level, (2) with the prisms stabilized so that llO the telescope beam always enters and leaves 1n the objective, (3) the objective and foca-l plane are brought as close as kpossible to the axis of the instrument commensurate with a given focal length and a given length of instrument parallel to the trunnion axis. B elongating the cylindrical case of the telescope the diameterof the case may be reduced and so the objective and focal plane may be brought closer to the axis and by re-arranging the parts both cross wires and objective might be placed on the axis and both incorporated in the stabilized system.

Thus in Fi 4'* and 4" the objective 6() has itsoptica centre on lthe trunnion axis 61. The prisms 62 and 63 are compound with the objective and reiiect the beam to the right and .slightly upwards into the singl reflectingr prism 64 on the face 65 of whic the foca plane is arranged, the centre of the cross wires being on the axis 61. The

eyepiece 66 completes the telescope. All

parts are stabilized bythe gyro except the eyepiece 66.

An alternative arrangement is shown in Figs. 5 4and 5b in which the observer looks along the axis.` The prism 68 is introduced to invert the image. The objective 60, the

prisms 62 and 68 and the cross wires 65 would all be stabilized-in this case.

'Another alternative arran ement I may adopt vis to stabilize the wIiole telescope system and arrange the parts so that the eyepoint of the telescope falls on the trunnion axis. .The rubber eye guard is attached to the outer case and moves with the ship but the whole ofthe optical parts of the telescope including the eye lens are attached to the prism plate. In Fi s. 6, 6b and 6 the prism plate 70 carries' t e objective'71, the doubly reflecting prism 72, the two singly'- reflecting prisms74; and 75, the field lens .76, and eye lens 77. The outer case 78 carries the rubber eye guard 79 and the window 80. The eye point of the telescope is -ari ranged to fall on the axis 61.

In perisco-pic sights and others in which there is difficult inv arranging stabilized prisms between t e objective and eyel iece I may arrange the stabilized prisms' to outside the telescope in front of the objective. In Figs. 7a and 7 b, 81 is an ordinary lperiscope with a single reflector 82 a't the upperl end and a treble refiector 83 atl the lower end next to t-he eye piece 84, the tube being lfitted with an objective 85 and window 86.

The reflector 82 is mounted on trunnion 87 to which a small pulley 88 isjfixed for thev `purpose of turning the prism 82 with respect to the tube of the periscope. The gyro and its fittings arranged as inFig. 1 are contained in the box. 89 .but have not been lshown in Figs. 7 and 7 b for the sake of simplicity. In this case a pulley 90 is vsubstituted for the prism plate of Fig. 1. The pulley 90 is one-half the diameter of pulley 88 and is connected to the latter by means of the band or belt 91. As the ship rolls the pulley 90 ldoes not roll withvit since it is stabilized by the gyroscope. Due tothe band 9'1 connecting this pulley to pulley 88, the latter will -f---be turned relatively to the gyroscope through an angle equal to vone-half the angle through lar displacement between it and the optical which th e ship rollsz thereby Vmaintaining the image of the object fixed in the field of view. a

Alternatively Iy may stabilize the prism 82 so that it rolls through the same angle as does the ship by `making the two pulleys 88 and 90 'of the same diameter, and then fit in front of the aperture 86 an erecting telescope having magnification 2. This is shown dotted in the figure as a Galilean telescope consisting of an objective 92 and a negative lens 93. In either arrangement the correotion for straying of the gyro is effected by means of the screw 94, which corresponds to the screw 20 in Fig. 1.

The arrangement of the several parts may take many different forms butall must have the common feature that the stabilized prism or prism combination must be inverting and, if placed4 outside the telescope, must move through one-half the angle of roll of the.

ship, or if a telescope having a magnification of two is laced in front of the stabilized prism, t e, latter must. be moved through an angle equal to that through which the ship rolls. I i' Having now particularlyldescribed and ascertained the nature of my said invention,

vfor the effects of angular motion of the plat- -form on the field of view, and y means for producing relative angular adjustment between the stabilizing device and the stabilized optical parts. l

i 2. In an optical instrument for use on moving platforms such as ships and thelike, the combination of a gyroscope, connections between the gyroscope and some of theoptical parts of the instrument for compensating. for the effects of angular motion of the platform on the field of view, and means for producing relative angular adjustment between the yroscope and the optical parts connected tereto to compensate for straying of the gyroscope. v

3. In an optical instrument for use on moving platforms such as ships and the like,

the combination of a gyroscope, connections between the gyroscope and some ofgthe optical parts of the instrument for compensating for the effects 'of angular motion of the. platform-on the field of view, means for` vmoving vthe gyrosco e parallel to. one of its trunnion axes, an means whereby such movement of the gyroscope produces anguparts stabilized thereby.`

4. In an optical instrument for use upon a moving platform such as a ship or the like, the comblnation of a casing, an objective and an eye-piece mounted on opposite sides of the casing in a normally horizontal plane passing through the center line of the casing, a gyroscopic stabilizing device and connections between the device and the remaining optical parts of the instrument for compensating for the effects of angular motion of the platform on the field of View.

5. In an optical instrument for use upon a movin platform such as a ship or the like, the com ination of a casing, an objective and an eye-piece mounted on opposite sides of the casing in a plane passing thro'ugh the center line of the casing, a gyroscopic stabilizing device, connections between the device and the remaining optical parts of the instrument for compensating for the effects of angular motion of the platform on the field of view, and means for producing relative angular adjustment between the stabilizing device and the stabilized optical parts. l

6. In an apparatus of the type described, an observation instrument mounted on a bodysubject to angular variations of position, an external reflector in optical relation to the observation instrument, gyroscopic stabilizing means for the refiector, and means for connecting said reflector and stabilizing means whereby relative motion between said stabilizing means and body is communicated to said refiector.

7. In an apparatus of the type described, an observation instrument mounted on a body subject to angular variations of position, a prism system in optical relation to the observation instrument, gyroscopic stabilizing means for the prism system, means for connecting said prism system and stabilizing means whereby relative motion between said stabilizing means and body is communicated to said prism system, and means for producing relative angular adjustment between the stabilizing means and the prism system.

8. In an optical instrument for use on an angularly moving platform, the combination of a casing carrying some of the optical parts of the instrument, a member rotatably` mounted on the casing and carrying another optical part, a gyroscope, a sup ort within which the gyroscope is mounte upon two trunnion axes, means for moving the gyroscope and the support parallel to one of the axes, a part connected to the member and a part connected to the support forming an operating connection between the member and the support and adapted to change the angular relation between them upon movement of the gyroscope and support parallel to one of the axes.

9. In an optical instrument for use on an angularly moving platform, the combination of a casing carrying some of the optical parts of the instrument, a member rotatably mounted on the casing and carrying another o tical plart, a gyroscope, a sup ort within w ich e gyrosoope is mounte u on two trunnion axes, means for moving t e gyroscope and the support parallel to one of the axes, and a connection between the member andthe support including a part provided with an inclined face and a part adapted to ed with an inclined slot engaging the ele' ment, and a connection between said members whereby the refiector may be stabilized by the gyroscope. l

11. A sightin device for use on an angularly movable p atform comprising a casing, a telescope bearing a fixed Arelation to'the casing, and comprising an objective, and eye piece and a prism system, a member rotatably mounted on, the casing and carrying a refiector, a gyroscope, connections between the glyroscope and member for compensating t e effects of angular motion of the platform, and means for producing relative anlar adjustment between the gyroscope and t e member.

12. A si hting device for use on an ang-ularly mova le platform comprising a casing, a telescope bearing a fixed relation to the casing, means external to the telescope whereby a distant object may be viewed through the telescope, and gyroscopic stabilizing means connected to said external means for maintaining the image of the object fixed in the field of view. l

13. A sighting device for use on an angularly movable platform comprisin a casing, a telesope bearing a fixed re ation to the casing, means whereby a distant object may be vlewed through the telescope, gyroscopic stabilizing means for said first named means and means for adjusting the stabiliz ing means.

14. An optical instrument for use on an angularly moving bodyA comprising a casing carrying some of the optical parts of the instrument, a member rotatably mounted on the casing' and carrying another optical part, a gyroscope, a support within which the gyroscope is mounted upon two trun 1,553,077 i l l Il nion axes, means for moving the gyroscope and the support parallel to one of the axes, a part connected'to the member and a part connected to the support forming an operatv ing connection' between the member and the` body, anoptical element mounted to move relatlvely to the body, a gimbal ring slidably mounted in the rame, a gyroscope for stabilizing the gimbal ring, means for i shifting the gimbal ring' automatically 'in one direction, a regulatory control for the gimbal ring4 operable in the reverse direction, connections between the gimbal ring and movable optical element for communieating to the element in a definite proper; tion the relative movement between the .gy-

roscope and the vbody .and means for adj usting theconnections by a sliding movement of the gimbal ring in the frame to change the relation between the gimbal ring and the movable optical element.

16. An optical instrument for yuse on an angularly moving body comprising a frame,

* a telescope provided with a movable reflectring device, a gyroscope, agimbal ring for the gyrosco e stabilized therebyand having trunnions s idably mounted in the frame, the frame being ada ted to turn about the trunnions, means havlng a cam and follower relation with the gimbal ring and controli lingly lcombined with the reflecting device for communicating to, the device lin a delinite proportion the relative movement -be- Itween the device and the body, and means to slide the gimbal ring to alter the cam and follower relation between the gimbal ring and the ,reflecting device.

17. An optical instrument for use on an angularly moving body comprising a frame,

a telescope provided' with a movable reecting device, a. gimbal ring provided with trunnions for slidably mounting the ring with respect to the frame, a gyroscope .pivotally mounted in the ,gimbal ring for stabilizing the ring, connections between the device and the gimbal ring for commuv nicatig-to the device in a definite proportion t'e relative movement between the device and the body, said connections including a cam and a follower, one belng associated with the device and thefother with the gimbal ring, means to change the relation of the cam and follower to adjust the device, relatively to the telescope, means for precessing the gyroscope about-the axis of the gimbal ring trunnions and means for precessing it about the axis of its own pivotal support. E

I JAMES BLACKLOCK HENDERSON.. 

